Fissaha Hiluf T, Kim Duckjong
School of Mechanical and Aerospace Engineering, Gyeongsang National University, Jinju 52828, Republic of Korea.
Gels. 2024 Nov 24;10(12):764. doi: 10.3390/gels10120764.
Adsorption heat pumps (AHPs) have garnered significant attention due to their efficient use of low-grade thermal energy, eco-friendly nature, and cost-effectiveness. However, a significant challenge lies in developing adsorbent materials that can achieve a high uptake capacity, rapid adsorption rates, and efficient reversible release of refrigerants, such as ammonia (NH). Herein, we developed and synthesized a novel salt-embedded covalent organic framework (COF) composite material designed for enhanced NH capture. This material was prepared by encapsulating sodium bromide (NaBr) within a porous and densely functionalized sulfonic acid-based COF. The COF was synthesized through a Schiff base (imine) condensation reaction, providing a robust platform for effective NaBr impregnation. The COF-based aerogel composite powder was investigated for its potential in ammonia-based AHPs, benefiting from both the porous, highly functionalized COF structure and the strong NH affinity of the impregnated NaBr. The composite adsorbent demonstrates an impressive NH adsorption capacity, adsorption rate, and stability. The exceptional NH adsorption performance of the COF-based aerogel composite powder is primarily attributed to the uniformly dispersed NaBr within the COF, the coordination of NH molecules with Na ions, and the hydrogen bonding interaction between NH and Br- ions. These findings highlight the potential of the salt-embedded COF composite for use in NH-based AHPs, gas separation, and other related applications.
吸附式热泵（AHPs）因其对低品位热能的高效利用、环保特性和成本效益而备受关注。然而，一个重大挑战在于开发能够实现高吸附容量、快速吸附速率以及制冷剂（如氨（NH₃））高效可逆释放的吸附剂材料。在此，我们开发并合成了一种新型的嵌入盐的共价有机框架（COF）复合材料，旨在增强对NH₃的捕获。这种材料是通过将溴化钠（NaBr）封装在多孔且功能密集的磺酸基COF中来制备的。该COF通过席夫碱（亚胺）缩合反应合成，为有效的NaBr浸渍提供了一个坚固的平台。基于COF的气凝胶复合粉末因其在基于氨的吸附式热泵中的潜力而受到研究，这得益于多孔、高度功能化的COF结构以及浸渍的NaBr对NH₃的强亲和力。该复合吸附剂展现出令人印象深刻的NH₃吸附容量、吸附速率和稳定性。基于COF的气凝胶复合粉末卓越的NH₃吸附性能主要归因于COF内均匀分散的NaBr、NH₃分子与Na⁺离子的配位以及NH₃与Br⁻离子之间的氢键相互作用。这些发现凸显了嵌入盐的COF复合材料在基于NH₃的吸附式热泵、气体分离及其他相关应用中的潜力。
